PSTricks plot polar

\documentclass[11pt]{article}
\usepackage{pstricks-add}
\pagestyle{empty}

\begin{document}
\setcounter{figure}{3}

\begin{figure}[h]
 \centering
  \psset{polarplot,labelFontSize=\scriptstyle}
\begin{psgraph}[yAxis=false,arrows=->](0,0)(-1,-1)(1,1){.5\textwidth}{!}
  \psplot[plotpoints=100,algebraic]{0}{3.5}{sin(x)*cos(4*x)}
\end{psgraph}
\caption{plot with trigonometric labels}\label{plt:trig}
\end{figure}


\end{document}